William A. Nierenberg

Long term impacts of increasing atmospheric carbon dioxide levels

This report addresses the question of the sources of atmospheric carbon dioxide, considers the distribution of the present carbon dioxide among the atmospheric, oceanic and biospheric reservoirs, and assesses the impact of significant increases in atmospheric carbon dioxide as reflected by the change in average ground temperature at each latitude. Possible direct impacts of increased atmospheric carbon dioxide levels on the biosphere are also considered. 50 figures, 33 tables.

Hyperfine structure and nuclear moments of protactinium-233

Abstract By means of the atomic-beam magnetic resonance method using radioactive detection, the hyperfine structure of 91Pa233 ( T 1 2 = 27.4 days ) has been investigated. Three low-lying states are found to be present in the beam, characterized by electronic angular momenta J = 11 2 , 9 2 and 7 2 and g values gj = −0.8141(4), −0.8062(15) and −0.7923(15) respectively. From these results it is inferred that the ground-state configuration of protactinium is almost certainly (5f)2(6d)1(7s)2. The nuclear spin is measured and found to be I = 3 2 and the magnetic dipole and electric quadrupole hyperfine structure coupling constants are measured to be A = ±595(30) MHz and B = ∓2400(300)MHz respectively. From a direct measurement, the nuclear moment is found to be μI = +3.4(0.8) n.m. From the hyperfine-structure constants and detailed calculations involving the electronic wave functions, the quadrupole moment is inferred to be Q = −3.0 barns.

Looking back 10 years

This paper is an update of the science of global warming. The point of departure is 1983 with the publication of the National Research Council/National Academy of Sciences report Changing Climate (1983). The present author was chairman of the report committee and considers this an appropriate time for an update. The advances (or retreats) in the overall science are reviewed with special emphasis on those that have critical policy implications.

The Nato Science Program

The nonmilitary program in science carried out under the aegis of Nato is described here by a former Assistant Secretary General for scientific affairs for Nato (1960–62), now a professor of physics at the University of California (Berkeley).

New directions in space: A report on the lunar and Mars initiatives

Abstract In 1989 President Bush committed the USA to the most ambitious and technically demanding objectives yet attempted in the space programme — establishing a permanent base on the Moon and subsequently mounting a manned expedition to Mars. These missions, together known as the Space Exploration Initiative, will place tremendous burdens on the countrys space budget and institutional structure, and especially on NASA. This article examines alternative technical and institutional possibilities, and argues that the technical options should be evaluated by an independent commission reporting to the highest levels of government rather than NASA itself.

Atomic beam magnetic resonance

Abstract The techniques of atomic beam research are reviewed with particular emphasis on most recent applications to low abundance isotopes and their nuclear properties. The well known space-quantization connection between the Zeeman and Paschen-Back conditions is rediscussed to show the effect on the observed transitions caused by anomalous hyperfine level ordering. In the second part the applications of the method to Am, Cm, Pu and Pa are discussed with respect to the elucidation of the ground state electronic wave functions. Current results are presented. The role of the hyperfine anomaly is discussed and the various atomic beam methods of measuring the nuclear magnetic moment directly are compared.